You are a special agent tasked with removing a monster capable of invisibility that has escaped from a military lab. It is nearly immune to everything and your only hope is to subdue it so it can be captured, It will take about 100 doses of sedative to stop it. You only have 300 darts use them well. Your darts also have the added bonus of staying where they land allowing you to see the areas where they hit. Two voids suck missed darts towards the corners.
The monster wont attack unless you run out of ammo- so don't! use your mouse to aim, your tranq gun auto fires